On the Dinosaar-Turtle Hnalogy 



NOTA 



DI 



G. R. WIELAND 



ACCADEMICO CORRISPONDENTE 



(Presentata da! Prof. Sen. GIOVANNI CAPELLINI). 



In my paper « Notes on the Armored Dinosauria. » I first gave general form to 

 the idea that there is a distinct structural parallel between the armor of turtles and 

 Dinosaurs but that while in the former fìxity and regularity of pattern were early 

 developed, in the latter bizarre patterns were assumed. The main thought was also 

 mentioned in a brief earlier paper of March 1909 in the American Journal of Science. 



But this view can be made rauch clearer now. Both Hay and later Von Huene 

 (News Jahrbuch Jdhrg. 1911 Bel. IT, pag. 146, 1912) agree in pointing out that 

 the so-called parietal extensions of Triceratops are in reality projections formed by the 

 fusion of elements which should be called dermo-parietals. I go further and state that 

 this is not only correct but that in ali probability there are two additional lateràl 

 dorsal elements fused with the squamosals-hypothetically the dermo-squamosals ; and 

 the hypothesis is clearly at liberty to go on and say that the horns as will may include 

 equivalent dermo-cornutal elements. Now any sudi dermocornuteds may, and both the 

 dermo-parietal and dermo-squamosal region must belong to the same deep dermogene layer 

 in the Ceratopsidae that in Polacanthiis and the Nodosauridae gives rise to what I descri- 

 ptively cali the lumbar-hip-carapace, which clearly results from the fusion of dermo-iliac 

 plates ; for in ali these instances whether in the skull region of Ceratopsids or the 

 post-dorsal region of Polacanthiis we see the bones of this primary deep dorsal layer 

 undergoing direct fusion with the endoskeleton, just as in the dorsum of the turtles. 

 Moreover just as I proved in the case of early turtles like Archelon and Toxochelys 

 Bauri the bones of this deep layer bear or are ridden by those of an outer superficial 

 layer. The demonstration of this superficial layer and its run in keels of course explained 

 the origin of the osteodermal carapace of Dermochelys. 



In the Ceratopsids, however, the outer osteodermal layer is represented by the 

 epoccipitals, as Marsh called them, which ride the dermo-parietal and dermo-squamosal 



